This is an application for a K99/R00 award for Dr. Courtney Lyles, PhD, a health services researcher at the University of California San Francisco, who is establishing herself as a young investigator examining health information technology use among diverse diabetes patients. This award will provide her with the support to transition to an independent academic researcher and to accomplish the following goals: 1) to become an expert in using comparative effectiveness research methods to understand the influence of online patient portal use on diabetes outcomes within racial/ethnic minority groups, 2) to employ qualitative and implementation science skills to understand barriers to portal use and to design a new approach to patient engagement, 3) to apply these rigorous approaches within an integrated delivery system with a mature electronic system (Kaiser Permanente Northern California) and a safety net public hospital system currently implementing an online patient portal (San Francisco General Hospital, SFGH). Dr. Lyles has assembled a multi-disciplinary mentoring team, led by Dr. Dean Schillinger, MD, who is an expert in designing and rigorously evaluating innovative interventions in this safety net setting. This team also includes: Dr. Andrew Karter, PhD, a senior investigator at Kaiser with expertise in racial/ethnic healthcare disparities and comparative effectiveness methodologies; Dr. Rena Pasick, DrPH, a professor at UCSF who is a national leader in mixed methods approaches to understanding diverse patient preferences and needs; Dr. James Ralston, MD, MPH, an investigator at Group Health Research Institute who is an expert in patient portals and designing interventions utilizing technology to improve diabetes care; and Dr. Ralph Gonzales, MD, a professor at UCSF with deep expertise in implementation science and evaluating innovations within the safety net. Although there are marked racial/ethnic disparities in portal use nationwide, we know little about how to engage diverse patients in utilizing these technologies to extend their care beyond in-person office visits to improve diabetes self-care and management. In Aim 1, we will determine the link between portal use and diabetes outcomes (measured by adherence, missed appointments, and clinical control) among racial/ethnic minority patients at Kaiser. In Aim 2, we will transition to SFGH to qualitatively assess barriers to portal use among diabetes patients, employing user-centered design methodologies. And finally in Aim 3, we will design and test a novel program that addresses patient-reported barriers to use and trains SFGH patients to access the portal as part of their care routine. This work to actively engage a broader and more diverse group of patients in using new health information technology such as portals has the potential to improve health outcomes and reduce overall disparities in care.